Lubricant manufacture



May 22, 1951 w. N. AXE

LUBRICANT MANUFACTURE Filed April 25, 1949 IN1/EN TOR. W. N. AXE

BY A 7` TORMVS iatented May 22,

2,55"iiiI William N. Axe, Bartlesville, Okla., assigner io n Phillips Petroleum Company, a` corporation of Delaware Application April 25, 1949, serial No. 89,523

17 Claims. 1

This invention relates to the manufacture of lubricants, In one embodiment, it relates to the manufacture of lubricating oils by alkylating extract oils recovered from solvent refining of lubricating oil stocks. In one specic embodiment, this invention relates to the preparation of lubricating oils by catalytic alkylation of Waste extract oils with normal olens having at least 8 carbon atoms per molecule.

In order to produce the high quality mineral lubricating oils demanded in modern automotive engines, it is universal practice to treat distillatey and residual lubricating oil stocks with selective lsolvents to remove naphthenes, aromatics, asphalts, and the like, which have poor viscositytemperature characteristics. By means of countercurrent solvent extraction using solvents, such :as phenol, furfural, chlorex (beta,betadichloro ethyl ether) and the like, the Viscosity index of .raw oils may be increased as much as 30 units. Thus, by application of the various solvent exjl tractionprocesses, finished oils in the 100 V. If. A(viscosity index) range are available from a Wide variety of crude oils.

The extract oil derived fromv solvent extraction processes is of little or no value as: a lubricant. In many refineries this oil represents a disposal problemandat best the lighter extracts may be -.blended with gasoil cracking stock and the heav- :ier extract oils may be incorporated into fuel oils ,and road oils. Extract oils, such as thosederived .from typical Mid-Continent lubricating oil stocks, :are viscous, black, tarry fluids havingpoor vis- .cosity-temperature characteristics. Theviscosity of the extract oils at 210 F. exceeds the values for corresponding Waxy ralinates by 20. to 150 The I have now discovered a method whereby the 'so-called extract oils can beconverted into medi- Auni viscosity indexy oils having'. desirable charac- "teristics both as automotive crankcase oils A,and 'Diesel engine lubricants. those derivedv from the solventA extraction of Extract oils,z such as 2 SAE 10, 20 and 30 oils, When treatedI With se,- lecte'd olefins in the presence of an alkylatio catalyst yield oils having positive viscosity index values ranging from about tof90. n

An object of' this invention is to` provide a method for the manufacture of lubricants.

Another object of this invention is. to provide a method for manufacturing lubricating oils from Waste extract oils by alkylation With nornal olens.

Still another object is to provide a method for making' valuable lubricating oils from extract oils obtained from solvent refining of lubricating oil stocks by alkylatin'g the extract oil With normal mono-olens having at least 8 and not more than 20 carbon atoms per molecule.

Other objects and advantages of thisl invention will be apparent to one skilled in the art upon study of the accompanying description and disclosure.

In one embodiment of the process of my in. vention, an extractl oil obtained from phenol ex.- traction of a typical Mid-Continent SAE 10 oil, characterized by a gravity of from about 13.4 to 133 API andviscosity of about 60 SUS at210 F. and' a viscosity index of about `l60, may be employed. The oil is dissolved in an equal volume of straight run naphtha 0r other substantially paraiiin'ic solvent, such as normal pentane, hexane, heptane, octane and the like. A straightch'ain' oleiin having at least 8 and not more than 20 carbon atoms per molecule, such as hexadeceIle-l, in an amount equal. to the weight of the` oilis added to the resulting solution to complete the alkylation feed mixture or solution. The alkylation feed is then pumped to an alkylation zone, maintained under alkylation conditions; containing an active liquid alkylation. catalyst, such as a liquid complex of boron fluoride and Water; hydrofluoric acid; aluminum chloride-hydrocarbon complex and the like. The eiiiuent from the alkylation zone is discharged into a catalyst separator from which catalyst is continuously recycled to the alkylation Zone and the hydrocarbonY phase is further processed for rern'oval of solvent and catalyst in a conventional manner. The total alkylate from this. operation hasl a viscosity of about SUS at 210 F. and"A a viscosity index of betweenl 45 and 50. The crude product may be subjected to vacuum distillation i 3 to prepare SAE 10 and 20 oils with V. I. values of '75 to 85 and a bright stock of somewhat lower viscosity index. These treated oils are colorstable and are resistant to oxidation and may be utilized as lubricating oils without further treatment.

n the practice of my invention, it is usually satisfactory to dissolve the extract oil in a parafnic solvent, preferably a parainic solvent having at least live and not more than ten carbon atoms per molecule, and it is still more preferable to use a substantially straight-chain parafiinic solvent, such as normal pentane, hexane, heptane and the like. The volume ratio of the solvent to oil may be in the range of from 0.25:1 to 5:1; however, a smaller or larger amount of the solvent may be used if desired. The temperature in the alkylation Zone may range from 50 to 200 F., however, it is usually preferred to operate at a temperature in the range of from 100 to 200 F.; it is to be understood that a higher or lower temperature may be beneficial in some cases. The exact temperature employed depends upon several factors, such as the catalystV used, the extract oil and the like. The alkylation reaction is preferably carried out in liquid phase; therefore only sufficient pressure is used to maintain the system in liquid phase. A residence time of from 30 to 100 minutes or more in the alkylation Zone is provided, depending on the particular olefin employed.

Due to the practical limitations imposed by viscosity, the present invention is preferably limited to the alkylation of extract oils from raw oil grades not heavier than about SAE 40. Thus, the extract oil from a Mid-Continent SAE 50 stock may have a viscosity of 240 SUS at 210 F. which on alkylation would be increased to a value exceeding 300 seconds. More viscous products are, however, within the scope of the invention, since they may be blended with other lubricating oils that are less viscous.

n order to obtain the necessary viscosity index improvement, the olefin should have at least 8 carbon atoms without substantial branching of the carbon chain. Lower normal olefins having from 3 to 6 carbon atoms enter into the alkylation reaction to produce stable oils with improved viscosity index; however, the latter property is not suiiiciently improved to result in a useful lubricant. Thus, in the alkylation of an extract oil from SAE 10 stock with pentene-l the viscosity index was raised from -150 to 50. The best results withrespect to viscosity index improvement are realized through the alkylation of extract oils with an oleinic material comprising substantially normal aliphatic olens having from 10 to 20 carbon atoms per molecule. Normal olens, preferably mono-l-olefins, containing from 8 to 20 carbon atoms per molecule usually are satisfactory for use in my process; however, in some cases normal olens having more than carbon atoms per molecule may be used to an advantage.

Preferred catalysts for the present alkylation process include boron fluoride-water complexes, e. g. (BF3-H2O), the complex prepared by saturating 40 to 50 per cent aqueous hydrogen fluoattacca' to the principles set forth by Wilson, Keith and Haylett (Ind. Eng. Chem., 28, 1065 (1936).

YFractionation and further viscosity index irnprovement may also be effected by countercurrent solvent extraction of the alkylated extract oils.

For a fuller understanding of this invention reference will be made to the accompanying diagrammatic drawing which illustrates one embodiment of the invention.

A lubricating oil stock to be rened by solvent extraction is passed through line 2 to solvent extraction Zone 4 where it passes upwardly and countercurrent to a suitable solvent, such as phenol, entering solvent extraction zone 4 by way of line 6. The raffinate oil phase, which contains the refined oil, passes from solvent extraction zone 4 through line 8 for further treating and handling as desired. The extract oil phase, which contains the waste oil, passes through line l0 to solvent recovery zone l2 where the solvent is removed from the extract oil by any suitable means, such as distillation, stripping or the like.

ride with boron fluoride, the complex prepared At least a portion of the solvent recovered from the yextract oil is recycled to solvent extraction zone 4 through lines I4, I6 and 6. If desired, a portion of the recovered solvent may be removed from the system through line I8. The extract oil from solvent recovery Zone i2 passes through line 20 to mixing zone 22 where it is mixed or dissolved in a suitable solvent, such as normal hexane, which enters mixing Zone 22 through line 24. The resulting solution of extract oil in the solvent passes from mixing zone 22 through line 26 to alkylation zone 26 which is maintained under suitable alkylation conditions. A normal olefin, such as pentadecene-l, which is to be the alkylating agent for the extract oil, enters alkylation zone 281through line 36 and the fresh liquid alkylation catalyst, such as boron iluoride-water complex, enters the alkylation Zone through line 32. The entire contents of alkylation zone 28 are thoroughly mixed by any suitable means, such as by mechanical stirrer 34. rlIhe mixture is maintained in alkylation zone 28 under alkylating `conditions and for a sufficient period of time to allow the alkylation reaction to take place. The reaction mixture eiiiuent from alkylation zone 28 passes through line 36 to catalyst separation zone 38 where the reaction mixture is allowed to separate into a hydrocarbon phase and a catalyst phase. The catalyst phase is withdrawn from catalyst separation zone 38 and at least a portion thereof is recycled to alkylation zone 28 by way of lines 40 and 32. If desired, a portion of the used catalyst may be withdrawn from the system through line 42 and passed to a regeneration zone, not shown, or used in any manner desired. The hydrocarbon phase passes from catalyst separation zone 38 through line 44 to stripping zone 46 where the solvent is stripped from the oil by any suitable means, such as by distillation. The solvent is removed from an upper portion of stripping zone 46 and at least a portion of the solvent is recycled to alkylation zone 28 through lines 48, 50 and 26. If desired, a portion of the solvent may be removed from the system through line 52. The lubricating cil is removed from the stripping zone 46 through line 54 for kfurther treating and handling as may be desired.

In the accompanying diagrammatic drawing, reference to some of the equipment, such as pumps, gauges, and other equipment which obviously would be necessary to actually operate assises the process, have been 'intentionally omitted. Only suflicient equipment has been shown to illustrate the process of the invention and it is intended that no undue limitation b'e read into this invention by reference to the drawing and discussion thereof.

The following examples illustrate the advantages of this invention.

EXAMPLE I An extract oil from a lMid-'Continent SAE l0 distillate was subjected to vdistillation at a pressure of 0.3 to 0.6 mm. of mercury to give the product distribution shown in Table `1.

The above distillate fractions were golden yellow in color when freshly distilled, but rapidly turned to dark brow-n on standing in stoppered bottles.

Extract fraction l (1250 g.) was dissolved in an equal volume of n-heptane in a glass alkylation reactor equipped with a mechanical stirrer. Approximately 55-cc. (.100 g.) of catalyst corresponding to the compositionBF3-H2O was added to the heptane solution of extract oil. To the catalystoil emulsion, hexadecene-l (250 g.) Was added dropwise over a period of lOO'minutes while maintaining the temperature of the reaction flask at 1Z0-125 F. At the conclusion of the vaddition of olen, the catalyst phase was withdrawnand the hydrocarbon phase was washed with several portions of water. Then-heptane was stripped from the oil in a stream of natural gas and -unreacted hexadecene (56 g.) was Yrecovered by distillation at l mm. pressure. The-.resulting crude alkylation product Was then distilled to yield three distillate fractions characterized in Table 2.

Table 2 D Viscosity Weight 1st' Pressure, Fraction of Oil, g. Teiip., mnh Hg SUS, SUS V. I

1 32 293-457 o. 55 97.7 l3s. 7 75 2 93 432-474 0. 40 205. 9 45. 4 74 3 78 474-550 0. 40 315. 3 51. 8 85 Residue.. 210 7389 228.7 68

The improvement in viscosity index as-a result of this treatment was quite striking. In view of the nature of the reactants in this reaction, the 8 per cent loss to sludge in the catalyst phase is not considered excessive. i

EXALPLE II 15'2 and a viscosity of 39.8 SUS at 210 F. The distillation residue had a viscosity index of 134 and a viscosity of 57 .'6 SUS at 210 F. The polymer definitely had viscosity index improving characteristics since a 1:1 volume blend of extract oil fraction 1 (Table 1 rof Example I) with the 152 viscosity index polymer resulted in an oil having a viscosity `index of 101', which is considerably higher than encountered in any .of the alkylate fractions. Infrared structure lanalysis showed considerable structural differences between'the alkylate andthe oil-polymer blend. It was concluded, therefore, that alkylation was the principal reaction in Example I.

It is to be understood that this invention should not be unnecessarily limited tothe above discussion and description and that rnodications and variations may be made without departing from the invention or from the scope ofthe claims.

I claim:

1. A process for the manufacture of a lubricating oil'from an extract oil including most of any na-phthenes, aromatics, and asphalts obtained by solvent refining of a lubricating Mid-Continent oil stock, which comprises dissolving said extract oil in a parafiinic hydrocarbon solvent containing at least 5 and not more than 10 carbon atoms per molecule in a volume ratio of solvent to oil in the range of 0.25: l to 5:1, passing the resulting solution to an alkylation zone maintained at an alkylation temperature in the range of .100 to 200 F., introducing into said alkylation Zone a straight-chain l-olefln having at least 8 and not more than 20 carbon atoms per molecule anda liquid alkylation catalyst, vmixing the total contents of said alkylation Zone, maintaining the resulting reaction .mixture in said alkylation Zone for a period 'of time of from 30 to 100 minutes, passing the reaction mixture effluent from said alkylation zone to a separation zone where said reaction mixture is separated into a catalystY phase and a hydrocarbon phase, and recovering a lubricating oil from said hydrocarbon phase.

2. A process for the manufacture of a lubricating oil from an extract oil including most of any naphthenes,.aromatics, and asphalts obtained by solvent reining of a mineral oil stock, which comprises dissolving said extract oil in a parafnic hydrocarbon solvent containing at least 5 and not more than 10 carbon atoms per molecule in a volume ratio of solvent to oil in the range of 0.2521 to 5:1, passing the resulting solution to an alkylation Zone maintained at an alkylation temperature in the range of to 200 F., introducing into said alkylation zone a straightchain 1-oleiin`.having at least 8 and not more than 20 carbon Vatoms per molecule and a catalyst comprising a boron fluoride-water complex, mixing the total contents of said alkylation zone, maintaining the resulting reaction mixture in said alkylation zone for a period of time of from 30 to 100 minutes, passing the reaction mixture effluent from said alkylation zone to a separation zone where'said reaction mixture is separated into a catalyst .phase and a hydrocarbon phase, and recoveringa lubricating oil from said hydrocarbonphase.

A3. A 4process for the manufacture of a lubricating oil from ran extract oil including most of any naphthenes, aromatics, and asphalts obtained by solvent refining of a mineral oilfstock, which comprises dissolving said extract oil in a parafnic hydrocarbon `solvent containing at least"'5 and not more thanlocarbonatoms per molecule in a volume ratio of solvent to oil in the rang of 0.2m to :1, passing the resulting solution to analkylation zone maintained at an alkylation temperature in the range of 100 to 200 F., introducing into said alkylation Zone a Straight-chain 1olen having at least 8 and not more than carbon atoms per molecule and a catalyst comprising anhydrous hydrogen uoride, mixing the total contents of said alkylation zone, maintaining the resulting reaction mixture in said alkylation zone for a period of time of from to 100 minutes, passing the reaction mixture eliiuent from said alkylation zone to a separation zone where said reaction mixture is separated into a catalyst phase and a hydrocarbon phase, and recovering a lubricating oil from said .hydrocarbon phase.

4. A process for the manufacture of a lubrieating oil from an extract oil including most of any naphthenes, aromatics, and asphalts' obtained by solvent refining of a mineral oil stock, which comprises dissolving said extract oil in a parainic hydrocarbon solvent containing at least 5 and not more than 10 carbon atoms per molecule in a volume ratio of solvent to oil in the range of 025:1 to 5: 1, passing the resulting solution to an alkylation Zone maintained at an alkylation temperature in the range of 100 to 200 F., introducing into said alkylation zone a straight-chain l-olen having at least 8 and not more than 20 carbon atoms per molecule and a catalyst comprising an aluminum chloride-hydrocarbon complex, mixing the total contents of said alkylation zone, maintaining the resulting reaction mixture in said alkylation zone for a period of time of from 30 to 100 minutes, passing the reaction mixture effluent from said alkylation Zone to a separation zone where said reaction mixture eliluent from said alkylation zone to a separation zone where said reaction mixture is separated into a catalyst phase and a hydrocarbon phase, and recovering a lubricating oil from said hydrocarbon phase.

5. In the process of claim 1 wherein the extract oil has a viscosity index of less than zero.

6. In the process of claim 1 wherein the lolen is pentadecene-l.

7. In the process of claim 1 wherein the l-olen is hexadecene-l.

8. In the process of claim l wherein the lolen is heptadecene-1.

9. In the process of claim l wherein the solvent in which the extract oil is dissolved is normal heptane.

10. In the process of claim 1 wherein the solvent for the extract is hexane.

11. A process for the manufacture of a lubricating oil from an extract oil including most of any naphthenes, aromatics, and asphalts obtained by solvent refining of a lubricating oil stock, which comprises dissolving said extract oil in a parafnic hydrocarbon solvent containing at least 5 and not more than 10 carbon atoms per molecule, passing the resulting solution to an alkylation zone maintainedV at a temperature in the range of 50 to 200 F., introducing into said alkylation Zone a normal aliphatic olen having at least 8 and not more than 2o carbon atoms per molecule and a liquid alkylation catalyst, mixing the total contents of said alkylation zone and maintaining the resulting reaction mixture in said alkylation Zone for a period of time of from 30 to 100 minutes, removing a reaction mixture from said alkylation zone and recovering from said reaction mixture a lubricating oil as the product of the process.

12.- In the process of .claim 11 wherein the alkylation catalyst is a boron fluoride-water com-J plex. y

13. In the process of claim 11 wherein the alkylation catalyst is hydrogen fluoride.

14. In the process o1" claim 11 wherein the alkylation catalyst is an aluminum chloride-1 hydrocarbon complex. A

15. A process for the manufacture of a lubricating oil from an extract oil including most of any naphthenes, aromatics, and asphalts obtained by solvent refining of a lubricating oil stock, which comprises dissolving said extract Voil in a parainic hydrocarbon solvent, passing the resulting solution to an alkylation Zone maintained at alkylation conditions, introducing into said alkylation zone a straight-chain olen having at least 8 carbon atoms per molecule and a liquid alkylation catalyst, mixing the total contents of said alkylation zone whereby the extract oil is alkylated with said olefin, removing a reaction mixture from said alkylation zone and recovering a lubricating oil therefrom. j

16. A process for the manufacture of a lubricating oil from an extract oil including most of any naphthenes, aromatics, and asphalts which comprises countercurrently treating a Mid-Continent lubricating oil stock with a solvent in a solvent extraction zone, passing the extract oil phase to a solvent recovery zone where the solvent is removed from said extract oil phase, dissolving the resulting extract oil in a solvent comprising substantially normal parain hydrocarbons containing at least 5 and not more than 10 carbon atoms per molecule, passing said solution to an alkylation zone maintained at an alkylation temperature in the range of to 200 F., introducing into said alkylation zone a straightchain mono-oleiin having at least 8 and not more than 20 carbon atoms per molecule and a boron uoride-water complex catalyst, mixing the total contents of said alkylation zone, maintaining the resulting reaction mixture in said alkylation zone for a period of time of from 30 to 100 minutes, passing the reaction mixture eiiiuent from said alkylation zone to a separation zone where said reaction mixture is separated int-o a catalyst phase and a hydrocarbon phase, recycling at least a portion of the catalyst phase to said alkylation Zone, passing the hydrocarbon phase to a stripping zone, removing the solvent contained in said hydrocarbon phase overhead from said stripping zone and recycling at least a portion of said solvent to Said alkylation zoneI and removing the lubricating oil from the lower portion of said stripping zone as a product of the process.

17. A process for the manufacure of a lubricating oil from an extract oil having a viscosity gravity constant of at least 0.9 and a Viscosity index at least as low as -50 obtained by solvent rening of a lubricating-oil stock, which comprises dissolving said extract oil in a paraiiinic tion catalyst, mixing the. total contents of saidk alkylation zone, maintaining the resulting reaction mixture in said alkylation zone for a period of time of from 30 to 100 minutes, passing REFERENCES CITED the reaction mixture effluent from said alkylation The following references are of record in the zone to a separation zone where said reaction me of this patent:

mixture is separated into a. catalyst phase and a hydrocarbon phase, and recovering a lubricating 5 UNITED STATES PATENTS oil from said hydrocarbon phase. Number Name Date 2,351,609 Haensel June 20, 1944 WILLIAM N- AXE- 2,383,056 Goldsby Aug. 21, 1945 2,463,872 Heinrich Mar. 8, 1949 

1. A PROCESS FOR THE MANUFACTURE OF A LUBRICATING OIL FROM AN EXTRACT OIL INCLUDING MOST OF ANY NAPHTHENES, AROMATICS, AND ASPHALTS OBTAINED BY SOLVENT REFINING OF LUBRICATING MID-CONTINENT OIL STOCK, WHICH COMPRISES DISSOLVING SAID EXTRACT OIL IN A PARAFFINIC HYDROCARBON SOLVENT CONTAINING AT LEAST 5 AND NOT MORE THAN 10 CARBON ATOMS PER MOLECULE IN A VOLUME RATIO OF SOLVENT TO OIL IN THE RANGE OF 0.25:1TO 5:1, PASSING THE RESULTING SOLUTION TO AN ALKYLATION ZONE MAINTAINED AT AN ALKYLATION TEMPERATURE IN THE RANGE OF 100 TO 200* F., INTRODUCING INTO SAID ALKYLATION ZONE A STRAIGHT-CHAIN 1-OLEFIN HAVING AT LEAST 8 AND NOT MORE THAN 20 CARBON ATOMS PER MOLECULE AND A LIQUID ALKYLATION CATALYST, MIXING THE TOTAL CONTENTS OF SAID ALKYLATION ZONE, MAINTAINING THE RESULTING REACTION MIXTURE IN SAID ALKYLATION ZONE FOR A PERIOD OF TIME OF FROM 30 TO 100 MINUTES, PASSING THE REACTION MIXTURE EFFLUENT FROM SAID ALKYLATION ZONE TO A SEPARATION ZONE WHERE SAID REACTION MIXTURE IS SEPARATED INTO A CATALYST PHASE AND A HYDROCARBON PHASE, AND RECOVERING A LUBRICATING OIL FROM SAID HYDROCARBON PHASE. 